Cyclocrinitids are marine dasycladaceous algae of Ordovician and Silurian age. Their skeletal elements consist of a seldom calcified main axis on which lateral branches are borne in whorls. Calcified heads commonly form at the termini of the laterals. In North America cyclocrinitids are represented by three genera: Anomaloides, Cyclocrinites, and Lepidolites. Anomaloides (=Anomalospongia) possesses laterals calcified throughout their extent. They expand gently outward, and no heads form. Three... Topics: Dasycladaceae, Fossil, Paleontology -- Silurian, Paleontology -- Ordovician, Paleontology -- North...
byNitecki, Matthew H; Williams, Patricia M. editor Managing Editor, Scientific Publications
Receptaculitaceae is considered an algal family within the order Dasycladales. The family is a coherent group that possesses anatomical characters common with the recent Dasycladales. the geographic and stratigraphic distribution of Silurian recetptaculitids is along the reef belt in a narrow zone from Iowa to Newfoundland. The ecological distribution of most Silurian species is within the reef complex; a few species are found in the carbonate inter-reef facies and a few in shaly rocks. -- The... Topics: Dasycladaceae, Fossil, Paleontology -- Silurian, Paleontology -- North America, Paleontology --...